Xenbase Image ID: 153205

Figure 3. frzb-1 mRNA Inhibits Skeletal Muscle Formation and Enhances Dorsoanterior Structures (A) Top, control embryo. Bottom embryo was injected into the vegetal pole with 200 pg of synthetic frzb-1 mRNA into each of the four blastomeres and allowed to develop to stage 36. Note the enlarged cement gland and shortening of the body in this dorsalized embryo. (B) Similar embryos after immunostaining with an antibody (MZ-15) labeling the notochord; the notochord is thickened in the frzb-1 dorsalized embryo. (C) Histological section through the eye of a normal embryo (top) and of an embryo injected as in (A) (bottom). The retina of the dorsalized embryo is folded multiple times, filling the enlarged eye. (D) Microinjection of frzb-1 mRNA into the marginal zone (400 pg/cell) leads to inhibition of trunk formation (bottom embryos). (E) Uninjected tadpole sectioned at the trunk level after staining with the skeletal muscle marker 12/101. (F) Sibling embryo injected with 250 pg/cell of frzb-1 mRNA into the marginal region of each of the four blastomeres. Note the decrease in the amount of 12/101 positive muscle and increase in notochord tissue ([So], somite; [No], notochord; [Ne], neural tube). (G) In situ hybridization at stage 103/4 showing expression of XMyoD in prospective skeletal muscle cells. (G′) frzb-1 mRNA inhibits XMyoD expression. (H and H′) Expression of XMyoD at late gastrula (stage 12 1/2) is inhibited by frzb-1 mRNA microinjection. (I and I′) Early expression (stage 10 1/2) of the organizer marker chordin is unaffected by frzb-1 ectopic expression. (J and J′) Late gastrula expression of chordin mRNA (stage 12 1/2) is expanded into the lateral marginal zone in frzb-1-injected embryos. Image published in: Leyns L et al. (1997) Copyright © 1997. Image reproduced with permission of the Publisher, Elsevier B. V. Larger Image Printer Friendly View

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